This paper proposes a standing-up support tool from chair for elderly people, and evaluates a standing-up action using the tool. The tool looks like a legless chair with armrests that are fitted up on the seat surface. The tool makes an elderly person appropriate standing-up posture by leaning the seat surface and lifting up the armrests. The tool has following characteristics, such as easy to use, and easy to maintain. Therefore, the tool can be used anywhere. Using the tool, measured values, such as acceleration, arm force, and standing-up time are improved. The tool facilitates standing-up action.